If you are interested in how
steel structures shape the built environment, this guide will provide you with interesting facts about steel structural systems.
Common steel structure types
Rigid portal frame
Rigid portal frame is a structural system composed of steel columns and steel beams connected by rigid connections, and is a typical representative of light steel structure. Rigidity, or "rigid connection", refers to the formation of an immovable fixed connection between components by welding or bolting, so that the steel components can share the external pressure. Its most notable feature is that the structural force path is clear, the internal force transmission is direct, and it can maintain overall stability when subjected to various external forces. This feature helps technicians improve design efficiency through standardized compilation during the design stage of construction drawings, greatly reducing construction errors.
This structural form is currently widely used in medium-span industrial plants, storage centers, logistics workshops, and other construction projects. In addition, it is very suitable for a modular construction method that combines factory prefabrication with on-site assembly. In the pursuit of high efficiency and low consumption in modern construction trends, its practicality and economy are becoming the preferred structural solution for more and more industrial projects.
The portal frame structure is usually composed of multiple key components, including vertical portal columns, upper steel beams, purlins for roof support, diagonal braces and tie rods for stabilization, a support system that runs through the entire structure, and a gable frame that forms a gable structure. Between different components, technicians usually use a standardized node connection design, which not only reduces the complexity but also facilitates modular production. The structural system is often used in light industrial plants. It has obvious integration characteristics and is particularly suitable for building forms with small roof loads and high requirements for internal space flexibility. Taking the span of 15 to 40 meters as an example, the portal frame within this range can not only provide good strength and stability, but also improve material utilization and ensure economical construction costs. In addition, when a larger space is needed inside the building, the effective use area can be expanded by adding a mezzanine structure, thereby realizing a three-dimensional configuration of different areas and enhancing the space utilization rate of the building.
Space frame structure
The space frame structure is a three-dimensional frame structure formed by a large number of steel bars arranged in a specific geometric pattern and connected by nodes. It has a strong bearing capacity and stable structure, and is particularly suitable for buildings that require large spans and lack intermediate supports. In daily life, the most common application of space frame structure may be the awnings of gas stations, which usually use spherical nodes, which have the advantages of high flexibility and strong plasticity.
Compared with the traditional beam-column frame system, the space frame structure has obvious advantages in structural stability, wind resistance, and large area coverage. It is often used in public buildings such as various stadiums, exhibition centers, and
industrial parks, most of which are open spaces and have strict standards for barrier-free vision. Thanks to standardized components and modular assembly, the on-site construction period of the space frame structure is greatly shortened, which is nearly 60% less than the time required for traditional construction methods. In addition, with the widespread application of BIM design software, it can perform accurate simulation and collision detection in the design stage to ensure that the actual construction is completed smoothly in strict accordance with the design.
Space truss structure
The space truss system is composed of triangular steel structure units as basic modules, assembled by staggered steel rods. Its core feature is to evenly distribute the axial force on the steel rods, greatly reducing the deadweight of the structure and improving the overall stiffness. This type of structure is particularly suitable for buildings that require a long-span roof system, which is common in exhibition halls, large industrial plants, and aircraft terminals.
Another name for a truss structure is "roof truss" because it is often used to support roof loads. In modern exhibition centers, roofs designed with space truss structures can not only create a wider interior space but also provide greater flexibility for exhibition layout, lighting, and ventilation system layout. Truss structure is also widely used in bridge construction. Its high strength and lightweight design can reduce the load on the lower structure, thereby reducing the cost of foundation construction. When combined with a cable structure or tensioning system, it can also achieve a more dynamic and artistic architectural appearance.
Steel structure corridor
Steel structure corridors are usually used as aerial passages between multiple buildings. They are widely used in urban complexes such as hospitals, campuses, and office parks. Compared with traditional structural forms, steel structure corridors have higher flexibility and engineering adaptability, and can be customized according to building spacing, elevation differences, and functional requirements. Its structural form mostly adopts steel beams or space truss systems, which are not only light in weight, high in rigidity, and clear in force, but also can effectively reduce the load impact on the original connected buildings. In addition, the prefabricated assembly method greatly shortens the construction period and reduces the damage to the environment caused by wet construction, which is particularly suitable for implementation in complex building environments.
In terms of the combination of function and aesthetics,
steel structure corridors also perform well. Taking hospitals as an example, corridors not only realize the rapid connection between wards, outpatient buildings, and emergency centers, but also ensure the isolation and barrier-free passage of medical transfer processes. In the industrial parks of the new era, corridors promote departmental collaboration. They are also often combined with landscape greening, lighting, and guidance systems to form highly recognizable spatial aesthetic symbols. For high-rise buildings, it can adopt a variety of construction methods, such as cantilever, cable, and hanging, to achieve stable structural performance and minimalist architectural language, while ensuring traffic safety, which also creates more possibilities for connectivity between different buildings.
Steel structure bridge
Bridges use steel as the main load-bearing component. With its advantages of high strength and light weight, steel structure bridges have become the mainstream construction form in modern bridge engineering. The ductility and processing precision of steel make bridges extremely flexible in the design stage, and they can be built in a suitable way in various complex terrains, such as mountain canyons, wide rivers, or dense urban transportation networks. Its common types include box girder bridges, arch bridges, cable-stayed bridges, and suspension bridges, and the structural system can be selected according to the span, load level, and construction conditions. Especially in scenes with complex geological conditions and limited space, it shows excellent convenience and adaptability.
In practical applications, steel structure bridges are widely used in various scenes such as urban expressway systems, highway hubs, highway-railway grade separations, cross-river and cross-river channels, and urban pedestrian bridges. For example, steel box girder bridges in urban elevated roads can be quickly assembled without interrupting traffic, reducing interference with the surrounding environment; in large-scale cross-river projects, steel arch bridges and steel truss bridges can provide better structural efficiency and construction safety. In the field of landscape design, steel structure pedestrian bridges not only provide convenient passage functions, but also often integrate lighting to become visual highlights connecting urban spaces. Combined with the application of modern coating systems and weathering steel materials, steel bridges can extend their durability while significantly reducing the number of maintenance times, helping cities build a green and sustainable transportation infrastructure system.
Strength and durability of steel structures
Strength
- Fast construction: Steel structure components are highly prefabricated and can be quickly installed on site, greatly shortening the construction period.
- Design flexibility: Steel has high strength and a large span, suitable for various building shapes and space layouts.
- Sustainability: Steel can be recycled, reducing construction waste and meeting the requirements of green and low-carbon development.
- Sturdiness: Steel structures have excellent tensile and compressive properties and can withstand extreme loads such as wind and earthquake.
Durability
- Thermal conductivity: Steel has strong thermal conductivity and needs to be combined with an insulation layer to control energy loss and thermal bridge effects.
- Acoustic performance: The steel structure itself has weak sound insulation and needs to be combined with sound-absorbing materials to improve its acoustic performance.
Performance characteristics of steel structures
Chemical composition: the "genetic code" of steel
The performance of steel is like a "recipe" carefully prepared by various chemical elements. Carbon is like the skeleton of steel. Too low a content will lead to insufficient strength, while too high a content will affect welding performance. Usually, the carbon content of construction steel is controlled at about 0.2% for the best. Manganese and silicon are important "reinforcers" that can significantly improve the toughness and strength of steel, while impurities such as sulfur and phosphorus are like latent destructive molecules and must be controlled below 0.05% to avoid the risk of embrittlement. What's even more amazing is that by adding a trace amount of alloying elements such as vanadium and titanium, the grain structure of steel can be made denser, just like putting on a layer of invisible armor for steel, which significantly improves its strength and weather resistance. Modern metallurgy has also found that adding copper can form a stable rust layer on the surface of steel. This "rust-proof" technology has created the famous weathering steel. Mechanical
Properties: the "physical fitness test" of steel
The strength index of steel is like the physical fitness data of athletes, which best illustrates its ability to withstand extreme conditions. Yield strength is equivalent to the critical point at which steel begins to "yield", while tensile strength is its last line of defense against fracture. However, what determines the safety of steel is often the elongation index, which reflects the degree of deformation that steel can withstand before breaking, just like the stretching capacity of a rubber band. The higher the value, the less likely the steel is to break suddenly when encountering sudden loads such as earthquakes. In cold areas, steel also needs to pass rigorous low-temperature impact tests (-40°C) to ensure that it will not break like glass. Interestingly, some special steels perform better in extremely low temperature environments. For example, the steel used in liquefied natural gas storage tanks can still maintain excellent toughness at ultra-low temperatures.
Processing technology: the transformation from raw materials to finished products
The processing process of modern steel is like a precise metamorphosis. The rolling process is like a giant rolling pin, pressing the hot steel billet into various standard profiles, from common H-shaped steel to precision steel pipes, which can be efficiently produced. Welding technology is the "sewing technique" of steel structures, but the temperature needs to be strictly controlled; otherwise, the weld area may become a weak link. Cold bending technology is particularly suitable for processing thin-walled components. It can bend steel plates into complex shapes like origami, but special attention should be paid to avoid stress concentration. With the advancement of technology, the combination of CNC machining and BIM technology has brought steel structure manufacturing into the intelligent era. Not only can the machining accuracy reach the millimeter level, but installation problems can also be discovered in advance through three-dimensional simulation. The most amazing thing is the super high-rise building like the Shanghai Tower. Its twisted shape requires the processing angle of each steel plate to be accurate. A slightly larger error will cause the entire installation system to fail.
Frequently asked questions
- How long is the service life of steel structures?
The service life of steel structures can generally reach more than 50 years. If regular maintenance and anti-corrosion treatment are done properly, the service life can exceed 100 years, meeting long-term use needs.
- Are steel buildings safe during earthquakes?
Steel structure has good ductility and earthquake resistance. Its structural integrity is strong, and it can effectively absorb earthquake energy. Even when a high-level earthquake disaster occurs, the overall structure is still protected from damage. It is very safe and reliable.
- Are steel buildings good for the environment?
Of course, steel is one of the few recyclable building materials. At the same time, the construction of steel structure projects has low noise and less dust, which not only reduces resource waste but also reduces carbon emissions, which is in line with the concept of green building.
- Can a steel building be expanded or added to later?
This is one of the significant advantages of steel structures. Steel structures are flexible to assemble, and their modular structure is convenient for later expansion. In addition, the secondary construction period is short, and the impact on the original structure is minimal.
- Is steel framing a good choice for building a home?
Yes. Steel structure buildings have three advantages: high strength, short construction period, and light structure. They can adapt to various terrains and climates and are an ideal solution for building modern houses.
- How to prevent steel from rusting and corroding?
You can prevent rust by spraying anti-corrosion paint, hot-dip galvanizing, or cladding coating, while combining regular maintenance and drainage design to effectively extend the service life.
